I agree with PrimForever_Gryffindor. I think that they are also taught a few spells too while they can do magic without being in trouble. That's the conclusion I came to when I first started reading the books. Don't worry, my friends were wondering that too.
I remember that the parents homeschool them just enough that they know how to read, write and do basic math. Because if you can't do those things, you can get anywhere in a magical career.
hahhah i like ur name!!!